The role of thymidine phosphorylase in the pathogenesis of allergic rhinitis.

The activity and distribution of thymidine phosphorylase (TP) in the nasal mucosa of patients with nasal allergy was examined and compared with those in healthy subjects. TP activity was analyzed by spectrophotometry and expression was examined by immunoblotting and immunohistochemical staining using a monoclonal antibody specific to TP. The expression level of TP detected by immunoblotting showed a correlation with the activity detected by spectrophotometry. In nasal mucosa obtained from patients with nasal allergy, the level of TP was significantly higher than that from normal subjects. Eosinophils, basal cells in mucosal epithelium and fibroblasts in nasal mucosa obtained from patients with nasal allergy were stained with anti-TP monoclonal antibody. Strong staining of eosinophils present in nasal discharge was observed. The present results indicate that an increased number of TP-expressing cells, especially eosinophils in nasal mucosa, might be associated with the pathogenesis of nasal allergy.